diff options
Diffstat (limited to 'mm/fremap.c')
-rw-r--r-- | mm/fremap.c | 101 |
1 files changed, 34 insertions, 67 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 3235fb77c13..9f381e58bf4 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -20,33 +20,28 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> -static inline void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, +static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { pte_t pte = *ptep; + struct page *page = NULL; - if (pte_none(pte)) - return; if (pte_present(pte)) { - unsigned long pfn = pte_pfn(pte); - - flush_cache_page(vma, addr, pfn); + flush_cache_page(vma, addr, pte_pfn(pte)); pte = ptep_clear_flush(vma, addr, ptep); - if (pfn_valid(pfn)) { - struct page *page = pfn_to_page(pfn); - if (!PageReserved(page)) { - if (pte_dirty(pte)) - set_page_dirty(page); - page_remove_rmap(page); - page_cache_release(page); - dec_mm_counter(mm, rss); - } + page = vm_normal_page(vma, addr, pte); + if (page) { + if (pte_dirty(pte)) + set_page_dirty(page); + page_remove_rmap(page); + page_cache_release(page); } } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); pte_clear(mm, addr, ptep); } + return !!page; } /* @@ -60,25 +55,12 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, pgoff_t size; int err = -ENOMEM; pte_t *pte; - pmd_t *pmd; - pud_t *pud; - pgd_t *pgd; pte_t pte_val; + spinlock_t *ptl; - pgd = pgd_offset(mm, addr); - spin_lock(&mm->page_table_lock); - - pud = pud_alloc(mm, pgd, addr); - if (!pud) - goto err_unlock; - - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - goto err_unlock; - - pte = pte_alloc_map(mm, pmd, addr); + pte = get_locked_pte(mm, addr, &ptl); if (!pte) - goto err_unlock; + goto out; /* * This page may have been truncated. Tell the @@ -88,26 +70,27 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, inode = vma->vm_file->f_mapping->host; size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; if (!page->mapping || page->index >= size) - goto err_unlock; + goto unlock; + err = -ENOMEM; + if (page_mapcount(page) > INT_MAX/2) + goto unlock; - zap_pte(mm, vma, addr, pte); + if (pte_none(*pte) || !zap_pte(mm, vma, addr, pte)) + inc_mm_counter(mm, file_rss); - inc_mm_counter(mm,rss); flush_icache_page(vma, page); set_pte_at(mm, addr, pte, mk_pte(page, prot)); page_add_file_rmap(page); pte_val = *pte; - pte_unmap(pte); update_mmu_cache(vma, addr, pte_val); - err = 0; -err_unlock: - spin_unlock(&mm->page_table_lock); +unlock: + pte_unmap_unlock(pte, ptl); +out: return err; } EXPORT_SYMBOL(install_page); - /* * Install a file pte to a given virtual memory address, release any * previously existing mapping. @@ -117,41 +100,27 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, { int err = -ENOMEM; pte_t *pte; - pmd_t *pmd; - pud_t *pud; - pgd_t *pgd; pte_t pte_val; + spinlock_t *ptl; - pgd = pgd_offset(mm, addr); - spin_lock(&mm->page_table_lock); - - pud = pud_alloc(mm, pgd, addr); - if (!pud) - goto err_unlock; - - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - goto err_unlock; - - pte = pte_alloc_map(mm, pmd, addr); + pte = get_locked_pte(mm, addr, &ptl); if (!pte) - goto err_unlock; + goto out; - zap_pte(mm, vma, addr, pte); + if (!pte_none(*pte) && zap_pte(mm, vma, addr, pte)) { + update_hiwater_rss(mm); + dec_mm_counter(mm, file_rss); + } set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff)); pte_val = *pte; - pte_unmap(pte); update_mmu_cache(vma, addr, pte_val); - spin_unlock(&mm->page_table_lock); - return 0; - -err_unlock: - spin_unlock(&mm->page_table_lock); + pte_unmap_unlock(pte, ptl); + err = 0; +out: return err; } - /*** * sys_remap_file_pages - remap arbitrary pages of a shared backing store * file within an existing vma. @@ -207,12 +176,10 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, * Make sure the vma is shared, that it supports prefaulting, * and that the remapped range is valid and fully within * the single existing vma. vm_private_data is used as a - * swapout cursor in a VM_NONLINEAR vma (unless VM_RESERVED - * or VM_LOCKED, but VM_LOCKED could be revoked later on). + * swapout cursor in a VM_NONLINEAR vma. */ if (vma && (vma->vm_flags & VM_SHARED) && - (!vma->vm_private_data || - (vma->vm_flags & (VM_NONLINEAR|VM_RESERVED))) && + (!vma->vm_private_data || (vma->vm_flags & VM_NONLINEAR)) && vma->vm_ops && vma->vm_ops->populate && end > start && start >= vma->vm_start && end <= vma->vm_end) { |